Experimental and theoretical insights into the adsorption mechanism of methylene blue on the (002) WO 3 surface.

Autor: Hkiri K; UNESCO UNISA Africa Chair in Nanoscience and Nanotechnology, College of Graduate studies, University of South Africa, Pretoria, South Africa., Mohamed HEA; UNESCO UNISA Africa Chair in Nanoscience and Nanotechnology, College of Graduate studies, University of South Africa, Pretoria, South Africa. hamza@aims.ac.za., Abodouh MM; Energy Materials Laboratory, Physics Department, School of Sciences and Engineering, The American University in Cairo (AUC), New Cairo, 11835, Egypt.; UNESCO UNISA Africa Chair in Nanosciences & nanotechnology, Pretoria, South Africa., Maaza M; UNESCO UNISA Africa Chair in Nanoscience and Nanotechnology, College of Graduate studies, University of South Africa, Pretoria, South Africa.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2024 Nov 06; Vol. 14 (1), pp. 26991. Date of Electronic Publication: 2024 Nov 06.
DOI: 10.1038/s41598-024-78491-3
Abstrakt: This work investigates the efficiency of green-synthesized WO 3 nanoflakes for the removal of methylene blue dye. The synthesis of WO 3 nanoflakes using Hyphaene thebaica fruit extract results in a material with a specific surface area of 13 m 2 /g and an average pore size of 19.3 nm. A combined theoretical and experimental study exhibits a complete understanding of the MB adsorption mechanism onto WO 3 nanoflakes. Adsorption studies revealed a maximum methylene blue adsorption capacity of 78.14 mg/g. The pseudo-second-order model was the best to describe the adsorption kinetics with a correlation coefficient (R 2 ) of 0.99, suggesting chemisorption. The intra-particle diffusion study supported a two-stage process involving surface adsorption and intra-particle diffusion. Molecular dynamic simulations confirmes the electrostatic attraction mechanism between MB and the (002) WO 3 surface, with the most favorable adsorption energy calculated as -0.68 eV. The electrokinetic study confirmed that the WO 3 nanoflakes have a strongly negative zeta potential of -31.5 mV and a uniform particle size of around 510 nm. The analysis of adsorption isotherms exhibits a complex adsorption mechanism between WO 3 and MB, involving both electrostatic attraction and physical adsorption. The WO 3 nanoflakes maintained 90% of their adsorption efficiency after five cycles, according to the reusability tests.
(© 2024. The Author(s).)
Databáze: MEDLINE
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